基于动力的预应力混凝土独塔斜拉桥承载力评估

结合桥梁现场环境振动试验和有限元模型修正,本文提出了一套基于动力的大型桥梁承载力评估方法,并应用该方法对一座预应力混凝土斜拉桥的承载力以及发生可能损伤后的承载力进行了分析评估。结果表明:该斜拉桥在当前状态下能够满足设计要求,不需要进行调索,但拉索面积折减与超载对桥梁承载力具有较大的影响。此类评估对于桥梁养护与维修、长期健康监测具有重要的意义。     

高原机车乘务员心理适应性选拔指标的研究

对西宁、格尔木机务段404名现职机车乘务员进行了以认知能力（4项纸笔检查：四数和计算、注意广度、知觉鉴别、数字译成符号）、反应速度及注意品质为主要项目的心理适应性调查。结果显示：预测合格符合率为91．72％，预测淘汰符合率为25．29％。认为：采用9分制评测的合格率和淘汰率可用于选拔高原机车乘务员应具备的心理素质。     

埋地金属管道非接触式磁记忆检测系统研究

对磁记忆检测技术原理及技术难点进行了介绍,通过阵列探头设计和信号处理手段解决了磁信号微弱的问题.采用阵列探头能够排除外界磁信号干扰,同时确保信号之间的一致性.经验证,这种设计能够获得埋地管道的地表磁场分布图,确定异常磁信号来源.所研制检测仪器能够有效进行埋地管道弱磁信号检测.     

考虑换船作业的长江干线集装箱船舶调度

考虑换船作业情况,建立以总运输成本最小为目标的非线性规划模型,提出包括船舶选择、挂靠港选择和运输任务指派三方面内容的不定期集装箱船舶调度优化方法;针对模型特点,考虑基因融合及基因修复,设计改进遗传算法对问题进行求解,应用案例获得集装箱船舶调度优化方案;采用多算例方法将考虑换船作业与不考虑换船作业的调度方案进行对比分析. 结果表明,考虑换船作业可以降低运输总成本,减少船公司的投入运力,有效提高投入运力的综合利用率,增强船公司的竞争力,为船公司制定船舶调度方案提供决策参考.     

汽车迎风面积测量方法的研究

汽车迎风面积是指汽车在行驶方向的投影面积,汽车迎风面积是求汽车空气阻力系数的必需参数。以前求汽车迎风面积测量方法较麻烦,测量精度不高。通过介绍和探讨利用数码照相机和计算机数据处理来测量汽车迎风面积的方法,为汽车迎风面积的测量提供新的方法和思路。     

Structural Multi-objective Probabilistic Design for Six Sigma

Uncertainties in engineering design may lead to low reliable solutions that also exhibit high sensitivity to uncontrollable variations. In addition, there often exist several conflicting objectives and constraints in various design environments. In order to obtain solutions that are not only "multi-objectively" optimal, but also reliable and robust, a probabilistic optimization method was presented by integrating six sigma philosophy and multi-objective genetic algorithm. With this method, multi-objective genetic algorithm was adopted to obtain the global Pareto solutions, and six sigma method was used to improve the reliability and robustness of those optimal solutions. Two engineering design problems were provided as examples to illustrate the proposed method.     

凿岩机器人液压系统自抗扰控制研究

给出凿岩机器人关节驱动液压系统的数学模型,对其进行降阶近似,使用自抗扰控制方法设计二阶控制器,并在不确定环境下进行仿真研究。结果表明,该控制器对于系统参数摄动和大负载干扰具有理想的鲁棒能力,控制过程快速、平滑,稳态精度高。     

Superpavel3技术在甘肃西长凤高速公路的应用

西长凤高速公路是甘肃省第一条采用Superpave高性能沥青混合料技术的高速公路,文中介绍这个技术在甘肃省应用的情况,提出一些施工时需注意技术要点,希望Superpave技术为甘肃省和其他省区的工程应用提供一些经验。     

四川省山区农村公路平曲线最小半径分析

基于对四川省川西山区农村公路的调查,分析了山区农村公路的交通特点和功能特点,根据汽车行驶速度和汽车行驶理论对山区农村公路平面线形设计中所采用的设计速度进行了分析研究,给出了山区公路圆曲线最小半径的设计参数取值原则和要求。     

Stiffness matrix derivation of space beam element at elevated temperature

Element stiffness equation is very important in structural analysis, and directly influences the accuracy of the results. At present, derivation method of element stiffness equation is relatively mature under ambient temperature, and the elastic phrase of material stress-strain curve is generally adopted as physical equation in derivation. However, the material stress-strain relationship is very complicated at elevated temperature, and its form is not unique, which brings great difficulty to the derivation of element stiffness equation. Referring to the derivation method of element stiffness equation at ambient temperature, by using the continuous function of stress-strain-temperature at elevated temperature, and based on the principle of virtual work, the stiffness equation of space beam element and the formulas of stiffness matrix are derived in this paper, which provide basis for finite element analysis on structures at elevated temperature.